This invention relates to network switches, and more particularly to bus-based network switches.
The rapid expansion of modern computer networks such as the Internet has fueled the need for faster network switches. Software-based routers and hardware-based network switches are used at intermediate points in networks to either route packets or make direct connections between input and output ports connected to various network nodes. The nodes can be other networks such as local-area networks (LAN's), computers such as PC's, servers, and workstations, or peripheral devices such as printers or storage devices.
Various topologies have been used for networks and for the network switches themselves. Ethernet uses a single bus, perhaps with several segments or branches, that connects to the various nodes. Token ring connects the nodes together in a loop or ring, with one node passing messages along the ring to the next node. Once the packet travels completely around the ring to the first station, the packet is removed.
Dual-ring Fiber-Distributed-Data Interface (FDDI) uses two parallel rings to connect the nodes. One ring provides a backup should a link failure occur on the other ring. While these topologies are used for the networks themselves, network switches that connect these kinds of networks together have tended to be cross-connect switches that allow any pair of ports to connect together through a switching fabric. Store-and-forward switches in a matrix-like switching fabric have also been used for network switches.
While these network switches have been useful, a network switch that uses a bus-like topology rather than a matrix-fabric topology is desired. An efficient bus-based network switch is desired.